This invention relates to magnetic tape drives and more particularly a locking mechanism for a file reel hub having improved locking characteristics.
In magnetic tape drives, tape is driven between a file reel and a machine reel past magnetic read/write heads. The file reels are removable and replaceable so that different files of magnetic tape can be processed. In high performance tape drives, the tape is accelerated from stop to a relatively high speed very quickly and decelerated at a like rate by motors driving the file and machine reels. This requires a non-slipping connection between the hub and the reels. Providing such a non-slipping connection is a particular problem for the file reel which must be easily removable and replaceable.
U.S. Pat. No. 4,397,428 - Smith, shows an actuator and locking mechanism which has been used successfully on tape drives, but slippage has been experienced. Any slipping that occurs causes read/write errors while the tape drive is in operation. In the hub of the above-identified patent, six pivoted "shoes" are cammed outwardly in a lever-like motion to engage the file reel. A pad of silicon rubber at the extremity of each lever-like shoe engages the peripheral surface at the center of the file reel. The engagement surface is relatively limited, occasioning the slippage problem and also resulting in accentuated wear and failure of the locking mechanism.
It is an object of the present invention to provide a locking hub for a file reel which has locking surfaces which engage the opening in the file reel throughout substantially the entire periphery.
It is another object of the present invention to provide a file reel having improved locking and wear characteristics.